Plating barrel



April 10, 1956 L. E. COLCLESSER 2,741,463

PLATING BARREL Filed Oct. 24, 1954 2 Sheets-Sheet 1 34 J 30 43 Z4 33 56 65 22 54 25" E I mm in @114 t IN VEN TOR.

April 10, 1956 L, E. COLCLESSER 2,741,463

PLATING BARREL Filed Oct. 24, 1954 2 Sheets-Sheet 2 W5 Ji0 Q 2 0 c i i United States atent C PLATING BARREL Lorren E. Colclesser, Chicago, 111., assignor to Merci! Plating Equipment Company, Chicago, ill a corporation of Illinois Application Gctober 24, 1951, Serial No. 252,820

4 Claims. (Cl. 25989) This invention relates to electroplating apparatus and, more particularly, to plating barrels to be used in electroplating systems.

The present invention is directed to electroplating systems generally and particularly to barrels for use in a system wherein small articles are to be electroplated in large batches. In this type or" electroplating system the small articles are inserted in a container, and the container is immersed in an electroplating bath or solution. Suitable electrodes are provided in the container and in the solution to obtain the necessary flow of plating current. During the plating operation, the plating solution within the barrel has removed therefrom the plating material and, accordingly, new plating solution must be introduced continuously to obtain good plating. To this end the walls of the container are provided with openings which permit expended plating solution to be withdrawn and replaced by fresh plating solution. There are in use today a large number of such electroplating systems which are substantially identical in construction. More specifically, the tank in which the plating container or barrel is immersed has dimensions which will receive and support in operating position a barrel having certain definite external dimensions. Accordingly, the capacity of a plating barrel cannot be increased by increasing its overall external dimensions. Instead, any increase in capacity must be obtained by providing more room within the barrel and by allowing a greater flow of plating solution through the solution of the barrel, thereby obtaining a higher rate of plating.

The amount of plating metal to be deposited on each article is minute and generally requires only a few minutes for its deposition. It is desirable to observe the rate of plating visually and to observe the contents of the plating barrel to insure that plating is proceeding at a uniform rate on substantially all of the articles contained therein. Heretofore it has been necessary to interrupt the plating operation to make visual inspections at periodic intervals of the articles being plated. This interruption was necessitated by the fact that the barrels are made of opaque or non-transparent materials, the only openings into the barrel being those minute openings through which the plating solution flows. It will be seen that it would be highly desirable to be able to continuously observe the progress of plating without interrupting the plating operation.

Accordingly, it is an object of the present invention to provide an improved electroplating apparatus and particularly an improved plating barrel.

More specifically, it is an object of the invention to pro-' vide an improved plating barrel that can be utilized in the present standard electroplating apparatus and yet has the important advantages set forth herein.

Another object of the invention is to provide a plating barrel construction that gives increased strengthand greater internal volume with the same overall external dimensions used heretofore in electroplating systems.

Still another object of the invention is to provide an 2,741,463 Patented Apr. 10, 1956 improved plating barrel having a greater area for the transfer of exhausted electroplating solution outwardly from within the barrel and fresh solution into the barrel.

Yet another object of the invention is to provide a plating barrel having improved means therein to increase the tumbling and redistribution of parts to be plated within the barrel.

A further object of the invention is to provide a plating barrel which is transparent whereby the progress of plating can be continuously observed.

A still further object of the invention is to provide an electroplating barrel of one-piece construction having a greater plating capacity, an increased operating efficiency and more simple construction.

Various other objects, advantages and features of the invention will be apparent from the following specification when taken in connection with the accompanying drawings wherein certain preferred embodiments are set forth for purposes of illustration. In drawings wherein like reference numerals refer to like parts throughout:

Fig. 1 is a general assembly view, partly in cross section, showing a standard electroplating system having incorporated therein a plating barrel constructed in accordance with and embodying the principles of the present invention;

Fig. 2 is an end view of the electroplating system shown in Fig. 1;

Fig. 3 is a perspective view of the plating barrel of the present invention;

Fig. 4 is an exploded view showing the various parts of the plating barrel of Fig. 3 before assembly;

Fig. 5 is an enlarged view in vertical sectionsubstantially as seen in the direction of the arrows along the line 5-5 of Fig. 3;

Fig. 6 is a view in vertical section as seen in the direction of the arrows along the line 66 of Fig. 5;

Fig. 7 is a further enlarged view in section as seen in the direction of the arrows along the line 7-7 of Fig. 6;

Fig. 8 is a partial view illustrating a modified construction of the plating barrel of this invention; and

Fig. 9 is a view in cross section substantially as seen in the direction of the arrows along the line 9-9 of Fig. 8.

Referring now to Figs. 1 and 2 of the drawings, there is shown a typical standard electroplating system in which the plating barrel of the present application has particular utility. The electroplating apparatus includes a tank20 which is substantially rectangular in shape and has an outwardly turned upper flange 22. Positioned on flanges 22 are a pair of brackets 24 and 26 that removably support the framework on which is mounted theplating barrel 28.

The frame includes a pair of spaced apart bars 30 and 32 which are disposed in substantial parallelism and extend the length of tarik20. Mounted on the ends of bars 30--32 but inside of the walls of tank 20 are frame members 34 and 36. Extending downwardly from the frame members 34 and 36 are a pair of hanger arms 38 and 40, respectively, which carry bearings on the lower ends thereof. The bearings at the lower ends of the hanger arms 3840 rotatably support the barrel 28, the barrel being driven by a mechanism to be described hereinafter.

The mechanism for rotating barrel 28 includes'a stub shaft 42 that is rotatably mounted in frame member 36. shaft 42 carries a pinion 44 that is driven by a pulley, 46 also mounted on shaft .2, pulley .46 being driven from a suitable source of motive power (not shown). Pinion 44 meshes with a gear 48 fixedly attached to one end of barrel 28 so that rotation of gear 48 rotates barrel 28. By

rotated on its bearings.

enemas entire frame and barrel assembly upwardly in the form of a bar 50 carried by the "frame members 34 and 36. Bar 50-.carries in the center thereof a fixture 52 having an opening 54 therein which can be readily engaged by a a hook or similar grappling member. Thebrackets 2'4 and 26 are open at the upper edge whereby to permit removal of the frame or barre'l by simply lifting the lframe upwardly.

Referring specifically to Fig. 1, it will be seen that the tank contains a suitable quantity of electroplating solution which extends upwardly to a'level designated by the numeral 56. The level of solution is maintained along the line 56 by means of a drain '58 positioned on the right hand side of tank '20 as viewed in Fig. '1. In order to aid circulation of solution from the bottom portion of the tank to the area of plating within th'e'barrel '28, a circulatingpump 60 is provided. .Pump 60 is mounted directly on an outer wall of tank 20 and 'has its intake positioned in an opening '62 formed in tank 20. A suitable motor 64 is prov'ided for-drivingpump 60. A pipe 66 is connected 'to the discharge port of pump 60 and serves to carry the pumped plating solution upwardly to discharge itinto the tank at a point adjacent the platingbarrel 28. Preferably, the bearing carried by the lower end of hanger arm 40 has an opening therein through which the discharge from pipe"66 can be directed. This arrangement provides a forced circulation of plating solution during the entire plating operation. V

The plating current is introduced through connections carried internally by the hanger arms 38 and 40, these connections being in turn connected to suitable electrodes positioned within barrel 28. The tank 20 carries a pair of 7 support bars 68 from which a plurality of anode bars 70 are suspended. The supports 60 are grounded to the tank 20 and form apart of the electrical circuit for the plating current as is diagrammatically indicatedby the wires 72 inFig. 2. The anode bars cooperate with the cathode structure carried in the barrel to provide current used in plating. The articles to be .plat'edwithin the barrelcontact the cathode structure positioned in the barrel and thereby form a portion of the conducting circuit. The 'current in effect passes between the cathode of "the anode bars through the plating solution to effect the plating operation as is well understood in the art.

ltwill be seen from the above description of the electrical circuit that suitable means must be provided for electrically insulating the plating barrel .28 and its associated'frame structure from tank 20. This can be done elfectively "by forming the brackets 24 "from a non-com ducting material.

Referring-now to Figs; '3 through 7 "of't'he drawings, one

, of the preferred forms of the p'latingbarrel '28will be described in detail. The 'barrel comprises generally a body 74, a cover 76 and apair'of endplates '78 andBO.

The cross section of body 74 is shown in Fig. '6 wherein the body is illustrated as being hexagonal in cross section but having only five sides, the sixth side being open. More specifically, there are provided a bottom 82, a pair of lower sides '84 and 86, and a pair ofupper sides 88 and 90. The-Sides-82 through '90 are formed from one piece of material in a manner .to be described hereafter.

Each of the sides 82, 84 and 86 is deformed inwardly as at points 92 to give addedstrength and to provide .increased tumblingof thearticles being plated.

V The end plates 78 and 80 are hexagonal in shapeiand' have dimensions slightly greater'thantheonter dimensions a of the body .74. Preferably, the body 74 is integrally con 'nected at each end to the associated end plate 78 :or 80 by welding orotherwise, solvent welding being nsedwh'en the material of construction is one of several plastics.

To aid in holding -the body 74 in the desired shape, retaining "strips "94, 96, '98, 100 and 102 are provided. The strips 94, '96 and 98 are substantially identical in shape and are triangular whereby to conform to the Q Le concave structure of the associated sides. It is to be noted also conform to the shape of the'associated sides 88 and 90. of sides 88 and 99 continue substantially parallel to the edges of the end plate 78 instead of being directed outwardly toward the uppermost .COIHCXS as are the other sides. Any suitable means may be .used for mounting the strips 98 through 192 on the end plate 78, but a preferred method is by solvent Welding when certain types:of plastics are used as the material of-con'structionfor the plating barrel. The retaining strips in addition' to hold the body 74 in position also strengthen and rigidity the barrel.

Additional fastening means are provided for securing the plates 78 and S9 to the body 74. .These additional fastening means are in the form of bolts 104 which are preferably formed of metals, these bolts being positioned at the corners of the end plates and body. More specifically, the bolts pass through apertures in the end plates *78 and are preferably countersunk as shown in "Fig. '7.

Apertures which are aligned with the apertures in the .end

plates 78 and 80 are formed in the walls of ;thebody 74. These latter apertures are threaded to engage the threaded ends 196 of bolts 104. Since the barrelis to be used in electroplating, any exposed metallic parts will accumulate plating material and, accordingly, must be covered 'to avoid deposition of plating metal thereon. Tothis endv inpositioning the cover 76 properly on barre128. ..-In addition, a pair of side clamping strips 114 and .116 are attached to the upper edges of the body 74 on the outside thereof and extend the length of body .74 to .abut adjacent faces of the end plates and receive fastener elements 104a therein. The strips 114116 provide means for clamping the .cover 76 .in operative position upon body 74. The cover 76 includes a rectangular body .118 whose length is substantially equal to the length of .body 74 and whose width corresponds to the distance between the upper edges of the body 74.. The longitudinally extending edges of cover 76 and the .facing edges of body 74 and strips 114-116 are complementarily bevelled whereby to obtain a tight fit. A pair of reinforcing andclamp ing bars 120 and 122 are firmly attached .to body 118 adjacent the ends thereofand extendin-a direction trans verse .to cover 76. The ends of bars .120122 are bevelled in a manner similar to the edges .of body .118 whereby to fit on the barrel body 74.

.A pair of clamps 124 are provided for firmly positioning cover 76 upon barrel 28 during the plating operation. Theseclamps are essentially .C-clamps having .ahookportion 126 at one end and an adjustable threaded screw 128 at the other. The books 126 extend over and .engage the strip 114 and the ends of the threaded screws 128.cngage beneath the edge of strip 116. Preferably, the clamps, 124 are positioned over the clamping bars .120 and 122 as shown in Fig. 3.

The body 74 and the cover 76 have-a plurality of aper tures 130 and 132, respectively, formed therein.

permits the formation of a substantially larger number of. apertures 1'30 and 132 and yet retain the necessary struc-' tural strength to contain and support a 'fullload of articles to be plated. This feature results in greater plating -elliciency and more rapid plating due to the more rapid re- More specifically, the upwardly extending portions.

placement of the depleted plating solution within barrel 28. I

An important feature of the present invention is the provision of a plating barrel that is formed from transparent materials. This structure permits continuous observation of the progress of plating without interrupting the plating operation. Any suitable transparent plastic can be used provided that this plastic fulfills the other requirements to be set forth hereafter. An example of a suitable type of plastic are the acrylic base resins and of particular utility are the methyl methacrylate resins sold under the trade names Lucite and Plexiglas.

7 The construction material for the barrel 28 must also have the necessary mechanical strength and must be unaffected by water and the solutions, including acid solutions, encountered in electroplating. It hasbeen found that the above-mentioned acrylic resins including the methyl methacrylate resins fulfill these additional requirements. In addition, these resins are readily formed and fabricated whereby to make construction of the barrel relatively inexpensive and simple.

More specifically, the body 74 of the present invention is made of one piece as described above, a fiat piece of plastic being used as the starting material. The plastic is heated until it can be bent into the shape shown in Fig. 6. After being bent into the desired shape, the plastic sheet is held in that shape until cooled whereby it retains the desired shape.

The various parts forming the one-piece plating barrel are joined by so-called solvent welding. This solvent welding is accomplished by dissolving a portion of the plastic on the faces to be joined, pushing the pieces together, and thereafter evaporating the solvent. When the pieces are pushed together, the dissolved plastic on the inner face flows together to form a substantially continuous joint and the subsequent evaporation of the solvent reconstitutes the plastic in its solid condition thereby forming the desired joint. Suitable examples of solvents for this solvent welding are the lower ketones, ester solvents, aromatic hydrocarbons, phenols, aryl halides, aliphatic acids, chlorohydrins, acetals and lower aliphatic halides. A preferred solvent is dichloromethane.

After the barrel has been completed by solvent welding the various parts together, it is desirable to anneal the barrel before use. Annealing is accomplished by heating the barrel to approximately 200 F. and cooling to room temperature. A preferred method is to heat an oven to the desired annealing temperature, such as 200 F., turn ofi the source of heat, place the barrel in the oven, and allow the oven and barrel to cool to room temperature. It has been found that joints formed in this manner are approximately 90 percent as strong as the original plastic material.

Although a preferred plastic, a preferred solvent and a preferred annealing process have been given for purposes of illustration, it is to be understood that other plastics may be used provided they meet the necessary requirements. It may be necessary to alter the welding solvent and the annealing process in accordance with the particular plastic chosen as the material of construction.

Referring now to Fig. 5, the manner of attachment of the gear 48 to the plating barrel will be described. It is to be noted that gear 48 is also formed of plastic, the same plastic as used in the barrel being utilized if desired. An aperture 134 if formed in the center of gear 48 to permit unimpeded flow of plating solution and to permit the introduction of electrodes through the bearing members. A plurality of bolts 136 are used to fasten gear 48 to the end plate 80, the heads of the bolts 136 being countersunk. Spacers 138 are interposed between the end plate 80 and gear 136 to hold these members in proper spaced relationship. Preferably, the bolts 136 pass through apertures in the spacers 138 to hold them in position. Inasmuch as the bolts 136 are generally formed of metal, inserts 140 are provided to cover the exposed portions of bolts 136 to prevent unwanted deposi- 144, respectively, to receive suitable bearing members and electrode structures. vided in the form ofa pair of outer flanges 146 and 148 and a pair of inner flanges 150 and 152. All of the flanges are suitably apertured with the apertures arranged concentrically. L

Referring now to Figs. 8 and 9, the modified form of corner construction has been shown. A corner bar'154 is provided in each of the corners of the body 74. These bars 154' extend the length of body 74 and it is into the ends of bars 154 that the screws 156 are threaded. It will be noted that there are no screws or bolts entering the body 74 as is the case of the structure shown in Figs. 6 and 7. This form of construction is particularly advantageous when the material of construction of body 74 is relatively thin whereby to make it diflicult to thread bolts or screws into the edges thereof.

It will be seen that there has been provided a plating barrel which fulfills all of the objects and advantages set forth above. More specifically, there has been pro vided a one-piece plating barrel of improved structure which can carry a much greater load than the plating barrels used heretofore. More specifically, up to 25 percent greater load can be carried due to the absence of internal obstructions in the barrel and the increased strength of the barrel, this increased load being obtained without increasing the overall dimensions of the barrel. In addition, increased tumbling is achieved due to the formation of the walls or the sides of the barrel. This feature gives a more uniform and more rapid deposition of plating metal.

The increased area of apertures in the walls permits passage of greater amounts of solution into and out of the barrel, thereby giving a greater rate of plating. It has been found that up to 30 percent more area can be provided with this construction of the barrel as compared with barrels used heretofore.

By using a transparent plastic, the progress of plating can be continuously observed without interrupting the plating operation and the end point of the plating operation can be detected readily. The use of the plastics described above also make the construction of the barrels simple, relatively inexpensive and result in a stronger and more rugged barrel.

Although certain preferred embodiments of the invention have been set forth for purposes of illustration and certain preferred materials of construction have been given by way of illustration, it is to be understood that the invention is not limited to the specific embodiments disclosed.

The invention is to be limited only as set forth in the following claims.

I claim:

1. A plating barrel comprising a body portion including a plurality of sides formed integral with one another and of plastic material, each of said sides intermediate the longitudinal edges thereof being deformed radially inwardly of the body portion substantially throughout the length of each side to provide increased strength therefor and each of said sides having the innermost extending portions thereof circumferentially offset from the longitudinal edges thereof and presenting gradually inclined inner surfaces to aid tumbling action within the barrel, a pair of end plates mounted on and closing the ends of said body portion, a plurality of separate retaining strips spaced peripherally around and mounted on the inner surface of each end plate and projecting axially toward one another, there being a retaining strip for each said inwardly deformed side of the body portion, and each said retaining strip having inwardly directed inner edges shaped to conform with and contact the outer surface Additional reinforcement is pro 7 of: the: corresponding; side of the hodyportiom along thfi inwardly deformed outer surfaceihereof: for. holding the sides iirtheir predeterminecishapez and position; .and means disposed" adjacent: the retaining: strips for securing the body portiomto the: endwplat'esz 22 A1 plating barrel asclaimediniclaim. 1, wherein the! meansasecuringthe body portion to the'end platesincludes elongated bars disposed internally" of the-body portion and extending throughout the length of the interior'surface: of: the. wall thereof and in" engagementxtherewith between the' adjacent. ends 0ft adjacent: retaining strips;

3,.A platingrbarrellas claimedin claim. 1, wherein thev means: securing; the body portion; to the end plates inand into the: body portion;

7 43A plating barrel as claimedv inlelaim L'Whereinthe adjacent longitudinal edges of one pair of adjacentssides provide aibarrel-openiug, and Whereint'reinforcingstrips extend entirely along said adjacent longitudinal edges-to abut the inner surfaces of the end plates; and wherein? fastener'elements extendthrough' the end plates and: intothe adjacent ends' of said reinforcing strips;

References Cited inthe file of this patent UNITED STATES PATENTS 1,165,346 Schulte' Dec. 21, 1915.- 2,479,323 Davis Aug. 16, 1949 2,491,925 Lazaro Dec. 20, 1949; 2,640,025 Lazaro May 26,- 1953: 

